Attic and wall fans are a common feature of many homes, and serve during periods of hot weather to provide much needed ventilation. In many cases such fan assemblies are provided with louvers which can be closed when the fan is not in use. However, it has been found that these louvers, which are usually of metallic construction, are not really effective in preventing heat losses through the fan opening. Thus, in the case of an attic fan mounted in a ceiling opening, expensive heat can be lost through the closed louvers.
It is therefore the most important object of the present invention to provide a cover assembly for use with an attic fan or the like permanently mounted adjacent an opening in a wall or ceiling, in order to permit full, insulated coverage of the fan opening during seasons of the year when the fan is not in use so that heat losses through the fan opening are eliminated or at least minimized.
As a corollary to the foregoing, another object of the invention is to provide a fan cover assembly which includes a shell of dimensions to cover the fan opening and which is filled with a heat insulation material, along with means for securing the cover over the fan opening to maximize its effectiveness.